This invention relates to a color calibration alarm apparatus and method for use in an image-rendering device. The alarm apparatus, and associated method, make use of a sensor device, a comparing device and a latching device to facilitate comparison of printed or measured color values with expected or ideal color values at an appropriate time. If the measured color values differ sufficiently from the ideal color values, the alarm apparatus signals to the user that a calibration should be performed. The printed or measured color values are obtained from a test patch that is printed, preferably, on a break page between print jobs. The alarm device is placed at the output tray of an image-rendering device but may also be implemented as a separate stand-alone hand-held unit.
While the invention is particularly directed to the art of color calibration alarms for use in image rendering devices, and will be thus described with specific reference thereto, it will be appreciated that the invention may have usefulness in other fields and applications. For example, the invention may be used in any image-rendering device where calibration of the system to achieve a desired output is required.
By way of background, many color calibration systems are known. Some of these known systems are simple and elegant while others are more involved and require special color measuring equipment. A common feature of these known techniques, however, is that such techniques typically require the user or other individual to decide the time at which the calibration should be carried out. The problem with this approach is that, if a user waits until the color prints are perceptively and obviously of insufficient quality, then there may well have been a number of other previous prints made of sub-optimal quality. On the other hand, if calibrations are conducted on a regular schedule, many of the calibrations may be unnecessary—thus wasting valuable resources.
It would therefore be desirable to have a reliable system for indicating a proper time in which to conduct a calibration. In this regard, it would be advantageous to have a color calibration alarm that only reports to the user that a color calibration is necessary as opposed to a system that also reports the color detected and/or conducts the calibration. In this way, such a system could be adapted for use in a variety of different printing environments.
The present invention contemplates a new and improved color calibration alarm for use with image rendering devices that resolves the above-referenced difficulties and others.